It requires years of training and experience to develop the skills needed to set artificial teeth in a denture. The dental technician sets each tooth individually in a wax rim on an acrylic base plate, which is made from a model of the patient's jaw, the model having been cast from a negative impression of the patient's jaw made by the dentist. In setting the artificial teeth, each tooth must be at a particular angle of inclination and with the biting or grinding surfaces following the "Curve of Spee" wherein the protrusion of the teeth from the gums is reduced gradually from front to rear. The painstaking work is generally done by visual assessment, without templates or patterns.